1. Field of the Invention
The present invention relates to a flow controlling device for a discharge system, such as a drainage system, comprising a first vortex chamber with an inlet and an outlet and a second bigger vortex chamber with a peripheral inlet and a central outlet axial in relation to a vortex in this chamber, said second vortex chamber being at its inlet connected to the outlet of the first vortex chamber.
2. Prior Art
Such a flow controlling device is known from the accepted SE specification no. 457,121 and the corresponding WO-A-87/07048. Other flow controlling devices are known from the accepted DK specification no. 135,904, published GB specification no. 2,141,561 and U.S. Pat. Nos. 4,206,783 and 4,679,595. From these publications it is known to brake the flow of a liquid by leading it tangentially into a housing with an essentially circular cross section and which forms a vortex chamber. Common for these devices are that it is a prerequisite for the information of vortices and consequently for the establishing of the braking or controlling effect that the inlet flow into the vortex chamber takes place essentially perpendicular to the outlet flow dependent on the construction of the vortex chamber.
Within the field of controlling the flow of liquids and in particular within the environment sector there is an increasing need for not only a possibility to change the capacity by adjusting a controlling device but to an even higher degree a need for a possibility to control even smaller liquid flows than usual by means of a controlling device with a favourable characteristic and an acceptable cross section of the flow, clogging on account of solid or viscous impurieties in the liquid being thus avoided.